Method and extrusion die for making a structuring fabric

Abstract

An extrusion die makes a structuring fabric which has structuring-beads resting on sublayer-beads. The extrusion die has a flat first surface and a flat second surface, the first and second surfaces contact each other along a contact line. The first and second surfaces are inclined with respect to each other. The first surface has a first nozzle of a pair of nozzles for extruding a sublayer-bead and the second surface has a second nozzle of the pair of nozzles for extruding a structuring-bead on top of the sublayer-bead. The first nozzle has a substantially rectangular shape and the second nozzle has a shape that resembles a square with all four side edges bulged inwardly. Both the first nozzle and the second nozzle are located in close proximity to the contact line. The first nozzle has a first symmetry axis that is perpendicular to the contact line.

1 . An extrusion die for making a structuring fabric having structuring-beads resting on sublayer-beads, the extrusion die comprising:
 a substantially flat first surface; and   a substantially flat second surface, said substantially flat first surface and said substantially flat second surface contact each other along a contact line and said substantially flat first surface and said substantially flat second surface are inclined with respect to each other, wherein said substantially flat first surface contains a first nozzle of a pair of nozzles for extruding a sublayer-bead and wherein said substantially flat second surface contains a second nozzle of said pair of nozzles for extruding a structuring-bead on top of said sublayer-bead, wherein said substantially flat first nozzle has a substantially rectangular shape and wherein said substantially flat second nozzle has a shape that resembles a square with all four side edges bulged inwardly, wherein both, said first nozzle and said second nozzle are disposed in close proximity to said contact line, wherein said first nozzle has a first symmetry axis that is perpendicular to said contact line, and wherein said second nozzle has a second symmetry axis that is perpendicular to said contact line, wherein the first symmetry axis and the second symmetry axis contact each other at said contact line.   
     
     
         2 . The extrusion die according to  claim 1 , wherein a distance of said first nozzle to said contact line is smaller than 10% of a dimension of said first nozzle measured along the first symmetry axis and/or wherein a distance of said second nozzle to said contact line is smaller than 10% of a dimension of said second nozzle measured along the second symmetry axis. 
     
     
         3 . The extrusion die according to  claim 1 , wherein said first nozzle has a third symmetry axis that is parallel to said contact line and wherein said second nozzle has a fourth symmetry axis that is parallel to said contact line. 
     
     
         4 . The extrusion die according to  claim 3 , wherein a dimension of said first nozzle measured along the third symmetry axis substantially corresponds to a dimension of said second nozzle measured along the fourth symmetry axis. 
     
     
         5 . The extrusion die according to  claim 1 , wherein a dimension of said first nozzle measured along the first symmetry axis substantially corresponds to a half of a dimension of said second nozzle measured along the second symmetry axis. 
     
     
         6 . The extrusion die according to  claim 1 , wherein a dimension of said second nozzle measured along the second symmetry axis is between 60% and 80% of a largest dimension of said second nozzle measured along a line that is parallel to the second symmetry axis. 
     
     
         7 . The extrusion die according to  claim 1 , further comprising a plurality of equally formed pairs of nozzles that are distributed along said contact line. 
     
     
         8 . The extrusion die according to  claim 1 , further comprising a common supply chamber, said first nozzle and said second nozzle are connected to said common supply chamber within the extrusion die so as supply a same material to both said first and second nozzles. 
     
     
         9 . A method of producing a structured fabric having at least one structuring-bead resting on at least one sublayer-bead, the method comprises the following steps of:
 a) providing the extrusion die according to  claim 1 ;   b) providing a woven base fabric, the woven base fabric having a web facing side and a machine side;   c) extruding a sublayer-bead of polymeric material through the first nozzle of the extrusion die onto the web facing surface of the woven base fabric, wherein the sublayer-bead contains an upper foundation surface; and   d) extruding a structuring-bead of polymeric material through the second nozzle of the extrusion die onto a top of the upper foundation surface of the sublayer-bead.   
     
     
         10 . The production method according to  claim 9 , wherein the woven base fabric contains an upper layer defining the web facing side of the woven base fabric, wherein the upper layer is formed from upper cross-machine direction yarns that are interwoven with upper machine direction yarns, and wherein the sublayer-bead extends so deeply into the woven base fabric that the sublayer-bead creates a form-fit connection with at least some of the upper cross-machine direction yarns at their deepest points. 
     
     
         11 . The production method according to  claim 9 , wherein the substantially flat first surface of the extrusion die is substantially parallel to the web facing surface of the woven fabric during an extrusion process and wherein the substantially flat second surface of the extrusion die is inclined with respect to the web facing surface of the woven fabric during the extrusion process. 
     
     
         12 . The production method according to  claim 9 , wherein a distance of the first nozzle to the web facing surface of the woven fabric is larger than a distance of the second nozzle to the web facing surface of the woven fabric during an extrusion process. 
     
     
         13 . The production method according to  claim 9 , wherein the structuring-bead is extruded in step d) at a time when the sublayer-bead has not been cured yet. 
     
     
         14 . The production method according to  claim 9 , wherein a form of the upper foundation surface of the sublayer-bead substantially corresponds to a form of a lower surface of the structuring bead that rest thereon. 
     
     
         15 . The production method according to  claim 9 , wherein the upper foundation surface of the sublayer-bead is substantially flat. 
     
     
         16 . The production method according to  claim 9 , wherein in a thickness direction of the structured fabric, the sublayer-bead is provided substantially within a volume of the woven base fabric. 
     
     
         17 . The production method according to  claim 9 , wherein the structuring-bead forms a continuous line on the web facing surface of the woven base fabric. 
     
     
         18 . The production method according to  claim 9 , wherein the structuring-bead forms a straight line on the web facing surface of the woven base fabric or the structuring-bead has a wavy configuration. 
     
     
         19 . The production method according to  claim 9 , wherein the polymeric material extruded through the first nozzle to form the sublayer-bead and/or the polymeric material extruded through the second nozzle to form the structuring-bead is a silicone. 
     
     
         20 . The production method according to  claim 9 , wherein the polymeric material extruded through the first nozzle to form the sublayer-bead and/or the polymeric material extruded through the second nozzle to form the structuring-bead is a polyurethane. 
     
     
         21 . The production method according to  claim 9 , wherein the polymeric material extruded through the first nozzle to form the sublayer-bead and/or the polymeric material extruded through the second nozzle to form the structuring-bead is an acrylic material. 
     
     
         22 . The production method according to  claim 21 , wherein the acrylic material comprises at least one of the following components:
 N,N-Dimethylacrylamide;   2-Propenoic acid, 2-hydroxyethyl ester, polymer with 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane;   Isobornyl acrylate;   2-(2-Ethoxyethoxy)ethyl acrylate;   diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide;   [3-(2,3-Epoxypropoxy)propyl]trimethoxysilane;   acrylic acid; and   2-Hydroxyethyl acrylate.